Ashton Kutcher was reportedly "so in love" with Mila Kunis when they worked together on That 70s Show.

Speculation the two have been dating has been rife after they have been photographed together on several occasions, following Ashton's split with wife Demi Moore. They were last spotted on a weekend getaway to Carpenteria, California.

The pair have denied claims they are in a relationship, insisting they are just friends.

However, a source has told People Ashton, 34, has held a flame for Mila, 28, since they filmed the comedy series which aired from 1998 to 2006.

"He was so in love with her for a while when they worked together," the source said.

"He thought she was a goddess, was always talking about how beautiful she is. But she was with Macaulay [Culkin] for a lot of that time and also just generally gave off a not interested vibe."

But another source insists Ashton is not ready to dive into a relationship as he deals with his marriage break-up. The insider says they are just friends for the time being.

"He always talked about Mila like a little sister. They're definitely close pals and have been. I think if anything she's a good time for him. But he's not looking for anything serious," and insider said.

Representatives for the pair refused to comment on the claims. Ashton and Mila fuelled rumours of a romance as they were pictured dining on sushi and shopping for fruit and flowers during their three-day outing over the weekend.